Gravel & Topsoil Calculator
Enter the area's length, width, and depth to get the volume in bags, cubic yards, and approximate tons.
How it works
Volume is length × width × depth, with depth converted from inches to feet. Bag count divides volume by a typical bag's coverage (0.5 cu ft for gravel, 0.75 cu ft for topsoil), then adds your waste percentage and rounds up. Cubic yards divide volume by 27. Approximate weight multiplies volume by a typical bulk density (about 105 lb/cu ft for gravel, 80 lb/cu ft for topsoil).
Worked example
A 20 ft × 10 ft area at 3 in deep is 50 cu ft (20 × 10 × 0.25). For gravel at 0.5 cu ft per bag with 10% waste: 50 ÷ 0.5 = 100 bags, × 1.10 = 110 bags, or about 1.85 cu yd and roughly 2.6 tons.
Assumptions
- The area is treated as a simple rectangle at a uniform depth.
- Bag coverage and bulk density are typical figures — check your specific product's label.
- Bulk orders are usually priced and delivered by the cubic yard, not by bag.
Reference
General construction measurement practices: International Code Council (ICC).
Related tools
Frequently asked questions
How do I calculate how much gravel or topsoil I need?
Multiply length × width × depth (in feet) for cubic feet, then convert to bags, cubic yards, or tons.
How many cubic feet are in a cubic yard?
27 cubic feet (3 ft × 3 ft × 3 ft) make one cubic yard, the usual unit for bulk delivery.
Is the tons estimate exact?
No — it uses a typical bulk density that varies with material and moisture. Confirm with your supplier before ordering.